1 files changed, 27 insertions, 11 deletions
diff --git a/tools/clang-format/ClangFormat.cpp b/tools/clang-format/ClangFormat.cpp
index 6c50daf53834..ac0d0a8512f4 100644
--- a/tools/clang-format/ClangFormat.cpp
+++ b/tools/clang-format/ClangFormat.cpp
@@ -236,8 +236,15 @@ static void outputReplacementsXML(const Replacements &Replaces) {
 
 // Returns true on error.
 static bool format(StringRef FileName) {
+  if (!OutputXML && Inplace && FileName == "-") {
+    errs() << "error: cannot use -i when reading from stdin.\n";
+    return false;
+  }
+  // On Windows, overwriting a file with an open file mapping doesn't work,
+  // so read the whole file into memory when formatting in-place.
   ErrorOr<std::unique_ptr<MemoryBuffer>> CodeOrErr =
-      MemoryBuffer::getFileOrSTDIN(FileName);
+      !OutputXML && Inplace ? MemoryBuffer::getFileAsStream(FileName) :
+                              MemoryBuffer::getFileOrSTDIN(FileName);
   if (std::error_code EC = CodeOrErr.getError()) {
     errs() << EC.message() << "\n";
     return true;
@@ -249,12 +256,18 @@ static bool format(StringRef FileName) {
   if (fillRanges(Code.get(), Ranges))
     return true;
   StringRef AssumedFileName = (FileName == "-") ? AssumeFileName : FileName;
-  FormatStyle FormatStyle =
+
+  llvm::Expected<FormatStyle> FormatStyle =
       getStyle(Style, AssumedFileName, FallbackStyle, Code->getBuffer());
+  if (!FormatStyle) {
+    llvm::errs() << llvm::toString(FormatStyle.takeError()) << "\n";
+    return true;
+  }
+
   if (SortIncludes.getNumOccurrences() != 0)
-    FormatStyle.SortIncludes = SortIncludes;
+    FormatStyle->SortIncludes = SortIncludes;
   unsigned CursorPosition = Cursor;
-  Replacements Replaces = sortIncludes(FormatStyle, Code->getBuffer(), Ranges,
+  Replacements Replaces = sortIncludes(*FormatStyle, Code->getBuffer(), Ranges,
                                        AssumedFileName, &CursorPosition);
   auto ChangedCode = tooling::applyAllReplacements(Code->getBuffer(), Replaces);
   if (!ChangedCode) {
@@ -264,7 +277,7 @@ static bool format(StringRef FileName) {
   // Get new affected ranges after sorting `#includes`.
   Ranges = tooling::calculateRangesAfterReplacements(Replaces, Ranges);
   bool IncompleteFormat = false;
-  Replacements FormatChanges = reformat(FormatStyle, *ChangedCode, Ranges,
+  Replacements FormatChanges = reformat(*FormatStyle, *ChangedCode, Ranges,
                                         AssumedFileName, &IncompleteFormat);
   Replaces = Replaces.merge(FormatChanges);
   if (OutputXML) {
@@ -291,9 +304,7 @@ static bool format(StringRef FileName) {
     Rewriter Rewrite(Sources, LangOptions());
     tooling::applyAllReplacements(Replaces, Rewrite);
     if (Inplace) {
-      if (FileName == "-")
-        errs() << "error: cannot use -i when reading from stdin.\n";
-      else if (Rewrite.overwriteChangedFiles())
+      if (Rewrite.overwriteChangedFiles())
         return true;
     } else {
       if (Cursor.getNumOccurrences() != 0)
@@ -334,10 +345,15 @@ int main(int argc, const char **argv) {
     cl::PrintHelpMessage();
 
   if (DumpConfig) {
-    std::string Config =
-        clang::format::configurationAsText(clang::format::getStyle(
+    llvm::Expected<clang::format::FormatStyle> FormatStyle =
+        clang::format::getStyle(
             Style, FileNames.empty() ? AssumeFileName : FileNames[0],
-            FallbackStyle));
+            FallbackStyle);
+    if (!FormatStyle) {
+      llvm::errs() << llvm::toString(FormatStyle.takeError()) << "\n";
+      return 1;
+    }
+    std::string Config = clang::format::configurationAsText(*FormatStyle);
     outs() << Config << "\n";
     return 0;
   }